A color developer containing an aromatic primary amine color developing agent has been used in the past for formation of photographic color images, and at present, such a color developer plays a main role in the image formation method in color photography. However, such a color developer has a problem in that it is extremely easily oxidized with air or metals, and it is well known that the use of the oxidized developer for the formation of color images causes an increase in fog and an increase in the fluctuation of the sensitivity or gradation, with the result that the desired photographic characteristics cannot be obtained.
In particular, the fluctuation of photographic characteristics in continuous processing is apt to become large because of the shortened processing time that is being used in the recent photographic processing techniques. As the case may be, there is often a severe problem in that the processed photographic material becomes color-stained. In particular, when the desilvering step, rinsing-in-water step, etc., are shortened, such a problem is apt to occur frequently.
Various reasons, for example, as mentioned below, are considered to cause the color stain in the short time processing.
(A) The color developer deteriorates after being used or stored for a long period of time so that the photographic property thereof changes and the oxidation product of the developing agent in the developer adheres to the photographic material which is being processed, and as a result, the photographic material becomes color-stained because of an insufficient washing out of the adhered substance.
(B) The color developing agent is brought into the next bleaching bath or bleach-fixing bath, where the color developing agent is oxidized to cause the generation of fog or color stain.
(C) Substances which dissolve out from the photographic material which is being processed accumulate in the color developer so that the thus accumulated substances again adhere to the photographic material to cause color stain thereon.
(D) The dyes or sensitizing dyes contained in the photographic material cannot sufficiently be washed out so that the photographic material itself becomes colored.
(E) The bleach-fixing solution and the rinsing water or stabilization solution in the bath which follows the bleach-fixing solution deteriorate after being used or stored for a long period of time so that the photographic material which is being processed becomes color-stained.
In particular, in order to overcome the above-mentioned points (A) and (B), an improvement of the stability of the color developer to be used is an indispensable requirement, and various studies have heretofore been carried out up to the present.
For example, in order to improve the stability of a color developer, various kinds of preservatives and chelating agents have been investigated. For example, preservatives include the aromatic polyhydroxy compounds described in Japanese Patent Application (OPI) Nos. 49828/77, 160142/84 and 47038/81 (the term "OPI" as used herein refers to a "published unexamined Japanese Patent Application"), U.S. Pat. No. 3,746,544, etc.; the hydroxycarbonyl compounds described in U.S. Pat. No. 3,615,503, British Pat. No. 1,306,176, etc.; the .alpha.-aminocarbonyl compounds described in Japanese Patent Application (OPI) Nos. 143020/77 and 89425/78, etc.; the alkanolamines described in Japanese Patent Application (OPI) No. 3532/79, etc.; the metal salts described in Japanese Patent Application (OPI) Nos. 44148/82 and 53749/82, etc. Chelating agents include, for example, the aminopolycarboxylic acids described in Japanese Patent Publication Nos. 30496/73 and 30232/69, etc.; the organic phosphonic acids described in Japanese Patent Application (OPI) No. 97347/81, Japanese Patent Publication No. 39359/81, West German Patent No. 2,227,639, etc.; the phosphonocarboxylic acids described in Japanese Patent Application (OPI) Nos. 102726/77, 42730/78, 121127/79, 126241/80 and 65956/80, etc.; the compounds described in Japanese Patent Application (OPI) Nos. 195845/83 and 203440/83, Japanese Patent Publication No. 40900/78, etc.; the organic phosphonic acid series chelating agents described in Research Disclosure, Nos. 18837 and 17048, etc.
However, even by employing the above technique for improving preservability, it was still impossible to completely prevent the coloration and deterioration of the color developers. Regarding the sulfite ions which are known to be effective for preventing the coloration of developers, it is impossible to use a large amount of the sulfite ion when forming color images, contrary to the case of black-and-white developers, because the sulfite ion has a bad influence on the color forming property and has a solvent effect toward silver halides. In fact, recently the absence of the sulfite ion is rather considered favorable in view of the improvement of the color forming property. Accordingly, the coloration of color developers is becoming a more severer problem in this technical field.
If the time for the desilvering step, rinsing-in-water step, etc., which are carried out after the color development step is shortened under such a situation where the coloration and deterioration of the color developer to be used cannot completely be prevented, it is inevitable that the resulting stain of the photographic material in the color developer cannot sufficiently be washed out. Accordingly, the development of silver halide color photographic materials which are hardly stained has been strongly desired.
On the other hand, in the rinsing-in-water step, etc., in the processing procedure of silver halide photographic materials, it has recently become desirable to use less water for the purpose of preventing environmental pollution, economizing water resources and decreasing manufacturing cost. For example, S. R. Goldwasser, Journal of the Society of Motion Picture and Television Engineers, Vol. 64, pages 248-253 (May, 1955), "Water Flow Rates in Immersion Washing of Motion Picture Film" has proposed a method of reducing the amount of water to be used in the rinsing-in-water step where the water is run by a countercurrent flow system using plural stages of rinsing tanks. This method is utilized in various kinds of automatic developing machines as an effective means for water economization.
Apart from the above method, there is a different method where a stabilizer solution containing various kinds of chemicals is used in place of water in the rinsing step so as to reduce the amount of the processing solution to be used in the rinsing step (Japanese Patent Application (OPI) Nos. 8542/82, 14834/83, 132146/82, 18631/83 and 184345/84, etc.).
However, in any of the above methods, if the amount of the replenisher to be added to the final rinsing-in-water step or stabilization step is reduced, the removal of the iron complex existing in the bleaching solution or bleach-fixing solution and, in particular, the removal of the developing agent existing in the developer would be insufficient with the result that yellow, magenta and cyan stains which would be derived from the iron complex or developing agent would increase after storage. Anyway, all of the known methods have some defects.
In particular, in the case of reflective materials (for example, color papers), such stain would be amplified to several times because of optical reasons, as compared with light transmitting materials, and, therefore, even a slight stain would detract from the image quality. Accordingly, stain is an extremely important factor for evaluating photographic characteristics.